A sandwich beam with embedded internal resonators was studied. Two continuum Timoshenko beam models were employed to model the sandwich beam. One model treats the resonators as continuously distributed mass and the other with an effective mass density. Both models appear to describe the dispersion behavior and the bandgap structure of the original sandwich beam accurately. It was found that the local resonance frequency of the resonator is the key in determining the bandgap location. Numerical examples were presented to demonstrate the dynamic behavior of the sandwich beam including the attenuation and filtering of flexural waves with frequencies near the resonance frequency of the embedded resonators.

General rightsThis document is made available in accordance with publisher policies. Please cite only the published version using the reference above. Full terms of use are available: http://www.bristol.ac.uk/pure/about/ebr-terms AbstractHigh quality multi-walled carbon nanotubes (CNTs) grown at high density using a low temperature growth method are used as an alternative material to polymer sizing and is utilised in a series of epoxy composites reinforced with carbon fibres to provide improved physical and electrical properties. We report improvements for sizing-sensitive mechanical and physical properties, such as the interfacial adhesion, shear properties and handling of the fibres, whilst retaining resin-infusion capability. Following fibre volume fraction normalisation, the carbon nanotube-modified carbon fibre composite offers improvements of 146 % increase in Young's modulus; 20% increase in ultimate shear stress; 74 % increase in shear chord modulus and an 83 % improvement in the initial fracture toughness. The addition of CNTs imparts electrical functionalisation to the composite, enhancements in the surface direction are 400%, demonstrating a suitable route to sizing-free composites with enhanced mechanical and electrical functionality.

The luminescent properties of the Tm 3? /Tb 3? / Sm 3? ions in phosphate glasses and glass ceramics have been investigated for the generation of white light. The X-ray diffraction pattern of the glass ceramics reveals the presence of SrZnP 2 O 7 nano-crystals in the glass matrix after a suitable thermal treatment of the parent glasses. Bright white light emission of the glass and glass ceramic samples has been observed when the samples are excited with 357 nm light. Significantly increased luminescent intensity is observed from glasses to glass ceramics.